Recently, in consideration of brightness, contrast, power consumption, life time, volume, and weight of comprehensive functions, the thin film transistor liquid crystal display (TFT-LCD) is the only display device that catches up and even surpasses the cathode ray tube display. TFT-LCD has the advantages of excellent performance, good mass production, and a degree of high automation, therefore it has quickly become the main product in the current market.
In the conventional art, color TFT-LCD devices mainly adopt light emitting diodes (LED) with yellow phosphor as their backlight, but the color saturation is not high enough after adopting LEDs with yellow phosphor. In order to improve color gamut and achieve the bright-colored performance of the LCD device, backlight sources have mainly adopted blue light emitting chips with red and green emitting phosphor (B chip+RG phosphor), blue and red light emitting chips with green phosphor (BR chip+G phosphor), or blue and green light emitting chips with red emitting phosphor (BG chip+R phosphor).
However, in practice, the inventor found that the conventional art has some problems: although the current technology of BG chips with R phosphor adopts an independent driving method for the BG chips, the LED energy performance is not generally high. One important reason is that the BG chips with R phosphor are packaged in the same cup, so that the R phosphor absorbs G light generated from the G chip. However, because the efficiency of G light exciting the R phosphor is very low, most of the G light energy is lost, and the G light has a strong effect on the LED luminous flux.
Therefore, it is necessary to provide a new technical solution to solve the above problem.